An efficient synthesis of spiro- β-lactams having sulfenyl, sulfinyl and sulfonyl moiety

Abstract

An efficient and a facile route to spiro-β-lactams is described. 3-allyl-3-methylthio-β-lactams, which are synthesized through a Lewis acid mediated C-3 alkylation of the trans-3-chloro-3-methylthio-βlactams, undergo a facile intrasulfenyl cyclization reaction in the presence of halogens like bromine and iodine to give spiro β-lactams in good yield. These halospiro-β-lactams are then subjected to dehalogenation reaction using Raney-nickel. The resulting spiro-β-lactams are further transformed into their sulfinyl and sulfonyl derivatives by using m-chloroperbenzoic acid as an oxidant.

Recent Advances in the Synthesis of Spiro‐β‐Lactams and Spiro‐δ‐Lactams

“…However, a slight decrease in the yield was observed (e. g. 58% and 67%, for 127 a and 127 b brominated analogues, respectively). [54] A general mechanism proposed for the construction of the spirocyclic system relies on a first step of halogen interaction with the double bond followed by a stepwise nucleophilic addition-dealkylation sequence, which is in agreement with the seminal work of Turos and co-workers. [55] Scheme 42.…”

“…Bari et al synthesized halospiro-β-lactams 127 through cis-3allyl-3-methylthio-β-lactams 126 intrasulfenyl cyclization reaction in the presence of molecular iodine, affording iodospirocyclic products isolated as diastereoisomeric mixtures in good yield (69-83%) (Scheme 38). [54] These diastereoisomeric mixtures were subjected to dehalogenation reaction using Raneynickel to give 128 efficiently.…”

Synthesis, characterization, and antibacterial activity studies of β‐lactam capped silver nanoparticles

“…Our previous studies have proved the use of 3-phenylthio-β-lactams as an important synthons for C-3 functionalization reactions, thereby resulting in synthesis of a variety of novel β-lactams [24][25][26][27][28]. In continuation of such studies, we became interested in finding out the method to increase the utility of these compounds.…”